Surgical rod scorer and method of use of the same

ABSTRACT

A surgical rod scorer is provided. The surgical rod scorer includes a pair of elongated shaft members that are pivotably coupled to one another and movable from a spaced-apart configuration to an approximated configuration. Each of the shaft members includes a handle member that is configured for gripping by a user and jaw member that is configured to support respective first and second cutting assemblies thereon. The first and second cutting assemblies each include one or more cutting elements thereon configured and dimensioned to score surgical rod when the jaw members are in the approximated configuration and rotated about the surgical rod.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 14/863,524, filed on Sep. 24, 2015, now U.S. Pat. No. 9,907,596, which is a divisional of U.S. patent application Ser. No. 13/705,810, filed Dec. 5, 2012, now U.S. Pat. No. 9,144,447, which is a continuation-in-part of U.S. patent application Ser. No. 13/170,859, filed on Jun. 28, 2011, now U.S. Pat. No. 8,506,603, which is a continuation-in-part of U.S. patent application Ser. No. 12/904,817, filed on Oct. 14, 2010, now U.S. Pat. No. 8,714,427, which claims priority to, and the benefit of, U.S. Provisional Patent Application No. 61/278,924, filed on Oct. 14, 2009, the entire contents of each of these prior applications are incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to a surgical rod scorer and method of use of the same. More particularly, the present disclosure relates to a surgical rod scorer including a plurality of cutting elements aligned along a common scoring axis of the surgical rod scorer.

Description of Related Art

Disease, the effects of aging, or physical trauma resulting in damage to the spine has been treated in many instances by fixation or stabilization of the affected vertebra. A wide variety of spinal fixation apparatuses have been employed in surgical procedures for correcting spinal injuries and the effects of spinal diseases. Many types of spinal fixation apparatuses typically use a pair of longitudinal surgical rods running in a relatively parallel relationship to each other and the spinal column. The surgical rods are often bent into various complex shapes to provide the desired correction to a patient's anatomy. Typically, the surgical rods are solid.

In certain instances, the surgical rods may need to be cut. For example, typically, the surgical rods are longer than necessary in order to allow for the variability of a patient's anatomy and, therefore, need to be cut once a construct, e.g., a spinal fixation apparatus, is completed. Also, the surgical rods may need to be cut in revision surgeries where the hardware of the construct that was implanted needs to be removed so additional hardware can be implanted and/or additional corrections can be made. In either of the foregoing cutting scenarios involving surgical rods, it may prove advantageous to transfer minimal force to the construct and/or surrounding anatomy and to provide a smooth edge to the cut rod so it does not damage surrounding tissue and vasculature.

Conventional devices employed to cut the surgical rods utilize a “bolt cutter” approach, see U.S. Pat. No. 5,836,937 issued to Holmes. Typically, devices of this type include a surgical rod cutter having a set of jaw members rotatably connected to one another. The jaw members are capable of opening and closing upon actuation thereof. Each of the jaw members includes a cutting blade that opposes a cutting edge on the other jaw member. However, this type of rod cutter applies a large amount of force to the surgical rod, which, in turn, effectively shears the surgical rod apart; this type of rod cutter does not provide a clean cut of the surgical rod. That is, this force is, typically, applied to a portion of rod that is to be removed and, thus, creates a burr on a cut edge of the surgical rod after the surgical rod is cut.

SUMMARY

As aspect of the present disclosure provides a surgical rod scorer. The surgical rod scorer includes a pair of elongated shaft members that are pivotably coupled to one another and movable from a spaced-apart configuration to an approximated configuration. Each of the shaft members includes a handle member that is configured for gripping by a user and a jaw member that is configured to support respective first and second cutting assemblies thereon. The first and second cutting assemblies each include one or more cutting elements thereon configured and dimensioned to score surgical rod when the jaw members are in the approximated configuration and rotated about the surgical rod.

In certain instances, the cutting element(s) on each the first and second cutting assemblies may equal a plurality of cutting elements. In this instance, the plurality of cutting elements on the first cutting assembly may include three or more spaced-apart cutting wheels and the plurality of cutting elements on the second cutting assembly may include two or more spaced-apart cutting wheels.

In certain instances, the first and second cutting assemblies may include a bifurcated carriage that is defined by two sidewalls that are joined by a plurality of bushings seated within corresponding apertures extending through each of the two sidewalls. The plurality of bushings may be configured to support one or more cutting elements thereon.

Each bushing may include textured side portions that are separated by a smooth medial portion. In this instance, the textured side portions are configured to facilitate a secure engagement between the bushings and corresponding apertures and the smooth medial portions are configured to facilitate rotation of the cutting elements with respect to the bushings.

The two sidewalls of each bifurcated carriage may include two or more notched portions extending therethrough. The notched portion(s) of each of the two sidewalls may be configured to securely receive a corresponding support rod therein. The support rods may extend through corresponding apertures that extend through the jaw members of the shaft members. The support rods may be configured to exert a force on the bifurcated carriages when the jaw members are in the approximated configuration and surgical rod is positioned between the first and second cutting assemblies. The two sidewalls of each bifurcated carriage may include a generally arcuate medial portion.

Each of the operable distal ends of the shaft members may include a generally arcuate configuration corresponding to the arcuate medial portion of the two sidewalls to facilitate rotating the surgical rod scorer about surgical rod when the jaw members are in the approximated configuration and surgical rod is positioned between the first and second cutting assemblies.

Each of the shaft members may include an aperture therethrough for receiving a pivot pin therein. The pivot pin may be held in place within the apertures via a washer positioned between the shaft members and a pair of lock washers disposed in the aperture of each shaft member.

The first and second cutting assemblies may be removably attachable to the respective jaw members. In this instance, each of the jaw members includes a respective aperture therethrough that is configured to facilitate uncoupling the first and second cutting assemblies therefrom.

Each of the handle members may include a respective ring portion at a proximal end thereof. The ring portions may be configured to receive a finger of a user therein.

One or more interlocking teeth may be disposed on each of the shaft members. The interlocking teeth may be configured to releasably engage one another to maintain the jaw members in a predetermined approximated configuration when the shaft members are moved a predetermined distance toward one another.

As aspect of the present disclosure provides a method for cutting surgical rod in situ. A pair of opposing first and second jaw members of a surgical rod scorer are positioned around a surgical rod that has been previously affixed to a spinal segment via at least two bone anchors. The pair of first and second jaw members is approximated toward one another. The surgical rod scorer is rotated (or oscillated) about the surgical rod to score a portion of the surgical rod. The scored surgical rod is grasped with a surgical rod bender. The scored surgical rod is bent such that the surgical rod separates along the scored portion of the surgical rod.

The opposing first and second jaw members may be provided with respective first and second cutting assemblies having a plurality of cutting wheels with a first diameter thereon. In this instance, each of the first and second cutting assemblies may include respective bifurcated carriages that are defined by two sidewalls joined by a plurality of bushings that are seated within corresponding apertures extending through each of the two sidewalls.

Each bushing of the plurality of bushings may be provided with textured side portions separated by a smooth medial portion. The textured side portions may be configured to facilitate a secure engagement between the bushings and corresponding apertures and the smooth medial portions may be configured to facilitate rotation of the cutting wheels with respect to the bushings.

The two sidewalls of each bifurcated carriage may be provided with at least two notched portions extending therethrough. The at least two notched portions of each of the two sidewalls may be configured to securely receive a corresponding support rod therein. The support rods may extend through corresponding apertures that extend through the first and second jaw members of the shaft members.

The first and second cutting assemblies may be removably attachable to the respective first and second jaw members. Each of the first and second jaw members may include a respective aperture therethrough that is configured to facilitate uncoupling the first and second cutting assemblies from the respective first and second jaw members.

The first and second cutting assemblies may be replaced with first and second cutting assemblies having a plurality of cutting wheels with a diameter that is different than the first diameter.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein with reference to the drawings wherein:

FIG. 1 is a perspective view of a surgical rod scorer according to an embodiment of the present disclosure;

FIG. 2 is an exploded view of the surgical rod scorer depicted in FIG. 1 with components separated;

FIG. 3 is a top elevation view of the surgical rod scorer depicted in FIG. 1;

FIG. 4 is a cross-sectional view of the surgical rod scorer depicted in FIG. 3 taken along section line 4-4;

FIG. 5 is a partial cut-away top view of the surgical rod scorer depicted in FIG. 3 with a reciprocating member of the surgical rod scorer in an extended position;

FIG. 6 is an enlarged view of the area of detail depicted in FIG. 5;

FIG. 7 is a perspective view of a surgical rod scorer according to another embodiment of the present disclosure;

FIG. 8 is a perspective view of the surgical rod scorer depicted in FIG. 7 with an operable end of the surgical rod scorer unattached from a handle of the surgical rod scorer;

FIG. 9 is a perspective view of a surgical instrument configured for breaking surgical rod subsequent to scoring thereof;

FIG. 10 is a perspective view of the surgical instrument depicted in FIG. 9 coupled to surgical rod that has been previously scored by one of the surgical rod scorers depicted in FIGS. 1 and 7;

FIG. 11 is a schematic representation of a spine having a surgical rod affixed thereto via two pedicle screws;

FIG. 12 is an isometric view of one of the pedicle screws depicted in FIG. 11 with a lock-nut unsecured thereto for receiving surgical rod thereabout subsequent to affixing the pedicle screw to the spine;

FIG. 13 is a perspective view of the surgical rod scorer depicted in FIG. 1 coupled to the surgical rod affixed to the spine depicted in FIG. 11;

FIG. 14 is an enlarged, perspective view of the surgical instrument depicted in FIG. 9 attached to opposite sides of the scored surgical rod prior to flexing the surgical to break the surgical rod at the scored portion;

FIG. 15 is a perspective view of a surgical rod scorer according to another embodiment of the present disclosure;

FIG. 16 is an exploded view of the surgical rod scorer depicted in FIG. 15 with components separated;

FIG. 17 is a perspective view of the surgical rod scorer depicted in FIG. 15 with cutting assemblies separated from an operable head of the surgical rod scorer depicted;

FIGS. 18A and 18B are enlarged, perspective views of the cutting assemblies shown in an assembled and partially assembled configurations;

FIGS. 19A-19E are schematic plan views of the operable head including cutting assemblies of various sizes; and

FIGS. 20A and 20B are perspective views of a surgical rod scorer according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following description, as is traditional, the term “proximal” refers to a portion of a surgical instrument closer to the operator while the term “distal” refers to a portion of a surgical instrument farther from the operator. In addition, the term “cephalad” is used in this application to indicate a direction toward a patient's head, whereas the term “caudad” indicates a direction toward the patient's feet. Further still, for the purposes of this application, the term “medial” indicates a direction toward the middle of the body of the patient, whilst the term “lateral” indicates a direction toward a side of the body of the patient (i.e., away from the middle of the body of the patient). The term “posterior” indicates a direction toward the patient's back, and the term “anterior” indicates a direction toward the patient's front. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

With reference to FIGS. 1-6, and initially with reference to FIG. 1, a surgical rod scorer 2 according to an embodiment of the present disclosure is shown. The surgical rod scorer 2 is configured to score a surgical rod “R” (see FIGS. 4 and 10). The surgical rod scorer 2 may be utilized to score a surgical rod “R” prior to fixating the surgical rod “R” in a patient, or subsequent to fixation thereto, e.g., in-situ.

With continued reference to FIG. 1, the surgical rod scorer 2 is illustrated in an assembled configuration. In the assembled configuration, the surgical rod scorer 2 includes a handle 4. Handle 4 includes a proximal end 12. Proximal end 12 is configured to rotatably support a knob 14. A shaft 20 extends from the proximal end 12 and has a generally elongated configuration. A longitudinal axis “A-A” is defined through the handle 4 and the shaft 20. The shaft 20 includes a distal end 18 that supports a working or operable head 22. A drive member 6 (FIG. 2) is housed within the handle 4 and is configured to translate a reciprocating member 8 from a retracted position, to an extended position. One or more cutting elements 10 (FIG. 6) are operably coupled to each of the operable head(s) 22 of the shaft (cutting wheels 10 d-10 f are operably coupled to the operable head 22) and reciprocating member 8 (cutting wheels 10 a-10 c are operably coupled to the reciprocating member 8).

FIG. 2 illustrates an exploded view of the surgical rod scorer 2 with the parts separated. As illustrated in FIG. 2, the handle 4 includes two substantially identical handle half portions 4 a and 4 b that are operably coupled to one another via one or more suitable coupling methods. In the illustrated embodiments, handle half portions 4 a and 4 b are held in an assembled configuration via screws, i.e., handle half portions 4 a and 4 b are screwed together (FIG. 1). More particularly, handle half portion 4 a includes four apertures 1 a-1 d that are in vertical alignment with four corresponding threaded apertures 3 a-3 d operably disposed on the handle half portion 4 b (FIG. 2). Four screws 5 a-5 d are receivable within the four apertures 1 a-1 d on the handle half portion 4 a and are configured to engage the four threaded apertures 3 a-3 d on the handle half portion 4 b.

Handle half portions 4 a and 4 b each include respective proximal ends 12 a and 12 b. In the assembled configuration, the proximal ends 12 a and 12 b collectively define or form the proximal end 12 of the handle 4 (see FIG. 1 in combination with FIG. 2). In the assembled configuration, proximal end 12 of the handle 4 is configured to rotatably support the knob 14 thereabout (FIGS. 1 and 3-5). Specifically, an aperture or opening 16 (FIG. 5) of suitable proportion is operably disposed at the proximal end 12 (the opening 16 is shown engaged with a shaft 27 of the knob 14 and as such the opening 16 is not visible). More specifically, in the assembled configuration, opening 16 is defined by a semi-circular notch 16 b (FIG. 2) disposed at the proximal end 12 b and a semi-circular notch (not explicitly shown) disposed at the proximal end 12 a. Opening 16 is configured to maintain the knob 14 in a fixed orientation along the longitudinal axis “A-A” while the knob 14 is rotated such that the drive member 6 is movable with respect to the knob 14 and along the longitudinal axis “A-A,” described in greater detail below.

Each of the respective proximal ends 12 a and 12 b includes a respective cavity 11 a and 11 b, see FIGS. 2 and 5. In the assembled configuration the cavities 11 a and 11 b collectively define or form a cavity 11 that is configured to house a portion of the reciprocating member 8 including the drive member 6 therein such that the reciprocating member 8 including the drive member 6 is translatable within the cavity 11 from the retracted position, to the extended position when the knob 14 is rotated. Each of the cavities 11 a and 11 b includes a respective pair of shoulders 13 a (FIG. 5) and 13 b (FIG. 2) that are configured to contact a corresponding pair of flanges 15 a and 15 b that are formed adjacent respective proximal ends 26 a and 26 b of reciprocating member half portions 8 a and 8 b (FIG. 2) when the reciprocating member 8 has translated a predetermined distance distally. This predetermined distance corresponds to the cutting elements 10 a-10 c on the reciprocating member 8 being positioned adjacent the cutting elements 10 d-10 f on the operable end 22, as best seen in FIG. 6.

To facilitate gripping the handle 4, an exterior surface of the handle 4 may be textured or otherwise treated. For example, in one particular embodiment, the exterior surface of the handle half portion 4 a may include a plurality of raised projections or may include a knurled surface.

With continued reference to FIG. 2, handle half portions 4 a and 4 b include respective elongated shafts 20 a and 20 b that taper from the respective proximal ends 12 a and 12 b. In the assembled configuration the elongated shafts 20 a and 20 b collectively define or form the shaft 20 (see FIG. 1 for example). Each of the elongated shafts 20 a and 20 b includes a distal end 18 a and 18 b. In the assembled configuration, the distal ends 18 a and 18 b collectively define or form the distal end 18 of the handle 4 (see FIG. 1 in combination with FIG. 2). Each of the respective distal ends 18 a and 18 b is configured to support a respective operable head half portion 22 a and 22 b (FIG. 2).

Operable head half portions 22 a and 22 b may have any suitable shape. In the illustrated embodiments, operable head half portions 22 a and 22 b include a generally arcuate configuration having a respective notched opening 24 a and 24 b forming a “hook” or “C” shape (FIGS. 1 and 2). In the assembled configuration, operable head half portions 22 a and 22 b including their respective notched opening 24 a and 24 b collectively define or form the operable head 22 with a center opening 29 (FIG. 6) having the notched opening 24 (FIG. 1) that together are configured for insertion of a surgical rod “R” therethrough. The generally arcuate configuration of the operable end 22 with the notched opening 24 facilitates rotating the handle 4 including the reciprocating member 8 about surgical rod “R” when the surgical rod “R” positioned within the center opening 29 of the operable head 22, see FIG. 4.

Each of the operable head half portions 22 a and 22 b includes a respective plurality of apertures 21 a and 21 b (FIG. 2) that is configured to receive corresponding plurality of bushings 23 a and 23 b. Each of the plurality of bushings 23 a and 23 b is configured to receive a corresponding one of the one or more cutting elements 10, e.g., cutting wheels 10 d-10 f. Each of the plurality of bushings 23 a and 23 b is configured to facilitate rotation of the cutting wheels 10 d-10 f seated therein when the surgical rod scorer 2 is rotated (or oscillated) about surgical rod “R”. In certain embodiments, such as, for example, when rotation of the cutting elements is not particularly important, the plurality of apertures 21 a and 21 b may be configured to directly receive a corresponding one of the one or more cutting wheels 10 d-10 f.

In the assembled configuration, the operable head half portions 22 a and 22 b are disposed in a spaced-apart relation with respect to one another to facilitate movement of the one or more cutting wheels 10 d-10 f. More particularly, the operable head half portions 22 a and 22 b are spaced from each other at a predetermined distance that allows the one or more of the cutting wheels 10 d-10 f to be rotated (or oscillated) about the same scoring axis (FIGS. 1, 4 and 6).

One or more respective guide members 24 a and 24 b are operably disposed at predetermined locations along an inner facing surface of each of the handle half portions 4 a and 4 b (FIG. 2); two guide members 24 a and two guide members 24 b are shown on each of the respective handle half portions 4 a and 4 b. Each of the guide members 24 a and 24 b is configured to operably couple to a corresponding slot 25 a and 25 b operably disposed on respective reciprocating member half portions 8 a and 8 b of the reciprocating member 8. For illustrative purposes, only guide members 24 a are shown operably coupled to the corresponding slots 25 a, see FIG. 5 for example. Each of the guide members 24 a and 24 b is movable within the corresponding slot 25 a and 25 b and is configured to facilitate movement of the reciprocating member 8 along the longitudinal axis “A-A” and a centerline “CL” (FIG. 6) of the handle 4 when the knob 14 is rotated.

With reference again to FIG. 2, reciprocating member half portions 8 a and 8 b are illustrated. In the assembled configuration, the reciprocating member half portions 8 a and 8 b collectively define or form the reciprocating member 8. Reciprocating member 8 includes a generally elongated configuration and is operably disposed and translatable within the handle 4 including the shaft 20 along the longitudinal axis “A-A,” (FIGS. 1 and 4-5).

Reciprocating member half portions 8 a and 8 b operably couple to one another with one or more suitable coupling methods (FIG. 2). In the illustrated embodiment, a “snap-fit” or “press-fit” connection utilizes a plurality of indents 7 a and detents 7 b (FIG. 2) to couple the reciprocating member half portions 8 a and 8 b to each other. More particularly, the indents 7 a and detents 7 b are operably disposed along predetermined locations along an inner facing surface of the reciprocating member half portions 8 a and 8 b and couple the reciprocating member half portions 8 a and 8 b to each other.

Each of the reciprocating member half portions 8 a and 8 b includes respective proximal ends 26 a and 26 b and respective distal ends 28 a and 28 b. In the assembled configuration, the proximal ends 26 a and 26 b collectively define or form a proximal end 26, as best seen in FIG. 5. Likewise, in the assembled configuration, the distal ends 28 a and 28 b collectively define or form a distal end 28, as best seen in FIG. 1.

The proximal end 26 of the reciprocating member 8 is in mechanical communication with the knob 14. More particularly, in the assembled configuration, proximal end 26 of the reciprocating member 8 is configured to support drive member 6 such that the knob 14 is rotatable relative to the drive member 6 (FIGS. 1 and 3-5). Specifically, an aperture or opening 32 (FIG. 5) of suitable proportion is operably disposed at the proximal end 26 (the opening 32 is shown engaged with the shaft 27 of the knob 14 and as such the opening 32 is not visible). More specifically, in the assembled configuration, opening 32 is defined by a semi-circular notch 32 a disposed at the proximal end 26 a and a semi-circular notch 32 b disposed at the proximal end 26 b, as best seen in FIG. 2. Opening 32 is configured to receive the shaft 27 of the knob 14.

The proximal end 26 of the reciprocating member 8 is configured to house the drive member 6 therein. More particularly, each of the respective proximal ends 26 a and 26 b includes a respective elongated opening 17 a and 17 b defined by interior walls 44 a and 44 b, respectively, see FIG. 2. In the assembled configuration, the elongated openings 17 a and 17 b collectively define or form an elongated opening 17 (FIG. 5 illustrates the drive member 6 engaged in the cavity 17, as such the cavity 17 is not explicitly visible). Opening 17 is configured to house the drive member 6 therein such that the reciprocating member 8 including the drive member 6 is translatable within the cavity 11 of the proximal end 12 of the handle 4 from the retracted position, to the extended position when the knob 14 is rotated. As noted above, contact between the pair of shoulders 13 a and 13 b (FIGS. 2 and 5) and the corresponding pair of flanges 15 a and 15 b prevents the reciprocating member 8 from translating distally past a predetermined distance.

Distal ends 28 a and 28 b may have any suitable shape. In the illustrated embodiment, distal ends 28 a and 28 b include a generally arcuate configuration. More particularly, each of the distal ends 28 a and 28 b includes a respective generally concave medial portion 34 a and 34 b with two respective distally extending fingers 36 a and 36 b on each side of the concave medial portion 34 a and 34 b, as best seen in FIG. 2. The generally concave configuration of the distal ends 28 a and 28 b facilitates rotating the handle 4 including the reciprocating member 8 about surgical rod “R” when the surgical rod “R” is inserted through the notched opening 24.

Each of the distal ends 28 a and 28 b includes a respective plurality of apertures 38 a and 38 b (FIG. 2) that is configured to receive a corresponding plurality of bushings 40 a and 40 b. Each of the plurality of bushings 40 a and 40 b is configured to receive a corresponding one of the one or more cutting elements 10, e.g., cutting wheels 10 a-10 c. Other than receiving the respective cutting wheels 10 a-10 c therein, the plurality of bushing 40 a and 40 b function in a manner as disclosed above with respect to the plurality of bushing 23 a and 23 b.

In the assembled configuration, the distal ends 28 a and 28 b are disposed in a spaced-apart relation with respect to one another to facilitate movement of the one or more cutting wheels 10 a-10 c. Specifically, the distal ends 28 a and 28 b are spaced apart from each other at a predetermined distance that allows the one or more of the cutting wheels 10 a-10 c to rotate about the same scoring axis (FIGS. 1 and 4). More specifically, each of the distal ends 28 a and 28 b are offset from the respective inner facing surfaces of the reciprocating half portions 8 a and 8 b, as best seen in FIG. 2 with respect to distal end 28 b.

With reference again to FIG. 2, the drive member 6 is illustrated. Drive member 6 is configured to non-rotatably reside in each of the elongated apertures 17 a and 17 b. To this end, drive member 6 is complementary shaped to that of the elongated apertures 17 a and 17 b. In the illustrated embodiment, drive member 6 includes a generally rectangular shape; other shapes are contemplated. The drive member 6 is dimensioned such that respective interior walls 44 a and 44 b that define each of the elongated apertures 17 a and 17 b contact the drive member 6 from all sides to prevent the drive member 6 from rotating when the knob 14 is rotated. Thus, when the knob 14 is rotated, the drive member 6 is forced to translate along the longitudinal axis “A-A” instead of rotate thereabout.

A threaded aperture 42 of suitable proportion extends along a length of the drive member 6. In the illustrated embodiment, threaded aperture 42 extends the length of the drive member 6. The threaded aperture 42 of the drive member 6 is configured to operably couple the drive member 6 to the knob 14 and is configured to translate the drive member 6 including the reciprocating member 8 along the longitudinal axis “A-A.”

Referring again to FIG. 2, the knob 14 is illustrated. Knob 14 threadably engages the drive member 6. More particularly, the elongated shaft 27 includes a threaded distal end 46 that operably couples to the elongated threaded aperture 44 of the drive member 6 (see FIG. 4 in combination with FIG. 5). As noted above, the elongated shaft 27 of the knob 14 is positioned through the openings 16 and 32 of respective proximal ends 12 and 26 of the handle 4 and the reciprocating member 8.

Knob 14 is rotatable about the longitudinal axis “A-A” and fixed from translation along the longitudinal axis “A-A.” With this purpose in mind, an annular flange 48 is operably coupled to the elongated shaft 27 of the knob 14 and is disposed between the opening 32 at the proximal end 26 of the reciprocating member 8 and the opening 16 at the proximal end 12 of the handle 4, as best seen in FIG. 4. The annular flange 48 is configured to maintain the knob 14 in a fixed orientation along the longitudinal axis “A-A” while the knob 14 is rotated such that the drive member 6 is movable with respect to the knob 14 and along the longitudinal axis “A-A.” To ensure that the knob 14 remains fixed along the longitudinal axis “A-A,” the annular flange 48 includes a diameter that is greater than a diameter of the openings 16 and 32 of each of the proximal ends 12 and 26 of the handle 4 and the reciprocating member 8, respectively.

With reference to FIGS. 2 and 6, the plurality of cutting elements 10 is illustrated. The plurality of cutting elements 10 may be made from any suitable material. In embodiments, the material that the plurality of cutting elements 10 are made from is harder than the surgical rod material “R” is made from. For example, and in one particular embodiment, the plurality of cutting elements 10 is made from high-strength surgical stainless steel. The plurality of cutting elements 10 may be any suitable cutting elements known in the art. In the illustrated embodiments, the plurality of cutting elements 10 is in the form of six cutting wheels 10 a-10 f. While six cutting elements 10 a-10 f are described herein, it is within the purview of the present disclosure that any number of cutting wheels may be utilized, e.g., 3, 4, 5, 7, etc. The six cutting wheels 10 a-10 f provide an even score around surgical rod “R” with minimum rotation of the surgical rod scorer 2 about the surgical rod “R”. As can be appreciated, this facilitates scoring surgical rod “R” in situ where the surgical environment is typically confined to a relatively small working space.

The plurality of cutting wheels 10 a-10 f may be disposed in any orientation on the operable end 22 of the handle 4 and distal end 28 of the reciprocating member 8. In the illustrated embodiment, the cutting wheels 10 a-10 c are evenly spaced apart from one another along a peripheral edge of the distal end 28 (FIG. 6). Likewise, the cutting wheels 10 d-10 f are evenly spaced apart from one another along a peripheral edge of the operable head 22 (FIG. 6).

The cutting wheels 10 a-10 f may have the same or different diameter. In the illustrated embodiment, cutting wheels 10 b, 10 d and 10 f have the same diameter that is greater than a diameter of the remaining cutting wheels 10 a, 10 c and 10 e that have the same diameter (FIG. 6). The larger diameter of the cutting wheels 10 b, 10 d and 10 f provide a quicker and more thorough score of the surgical rod “R” when compared to the smaller cutting wheels 10 a, 10 c and 10 e.

With reference to FIGS. 11-14, operation of the surgical rod scorer 2 is described in terms of use of a method for scoring surgical rod “R” in situ to remove an unwanted portion of the surgical rod “R.”

Continuing with reference to FIGS. 11-14, the surgical rod “R” is affixed to a segment, e.g., vertebrae “V”, of spine “SP” via at least two pedicle screw constructs “PS”. One type of pedicle screw construct suitable for affixing surgical rod “R” to a spine “SP” is illustrated in FIG. 12. Pedicle screw construct “PS” is of the taper lock configuration and includes an outer housing or coupling 300 for receiving surgical rod “R” therethrough, a fixation or screw portion 302 for securing the pedicle screw construct “PS” to vertebrae “V” of the spine “SP,” a locking structure in the form of a collet 304 for securing the surgical rod “R” to the body 300 of the pedicle screw construct “PS” and a pin 301 for aligning the collet 304 with the coupling 300. For a more detailed description of the pedicle screw construct “PS” and operative components associated therewith, reference is made to commonly-owned U.S. Patent Publication Number 2010/0262196 filed on Apr. 23, 2010 by Barrus et al., the entire contents of which being incorporated by reference herein.

While the surgical rod “R” is disclosed herein as being affixed to the spine “S” via two pedicle screws “PS,” it is within the purview of the present disclosure that other types of bone anchors or bone anchoring systems may be utilized to affix the surgical rod “R” to the spine “SP.” For example, and in one particular embodiment, a laminar hook or the like (not shown) may be utilized to affix the surgical rod “R” to the spine “SP.”

Subsequent to securing the pedicle screw constructs “PS” to vertebrae “V” of the spine “SP” and securing the surgical rod “R” to the pedicle screw constructs “PS”, a portion of the surgical rod “R” may need to be removed. For example, an end portion of the surgical rod “R” may extend past the body portion 300 of the pedicle screw construct “PS” and may need to be removed, as best seen in FIG. 13. Or, for example, a portion of the surgical rod “R” between two of the pedicle screw constructs “PS” may need to be removed. In either instance, other than the positioning of the surgical rod scorer 2 along a different portion of the surgical rod “R,” the surgical rod scorer 2 is utilized in substantially the same manner. For illustrative purposes, the following description relates to removing an end portion of the surgical rod “R.”

In one particular surgical scenario, to remove the unwanted end portion of the surgical rod “R,” the reciprocating member 8 including the cutting elements 10 a-10 c, initially, is in the retracted position, see FIG. 7 for example. The operable head 22 of the surgical rod scorer 2 is placed or positioned around the surgical rod “R,” see FIG. 13, for example. In one particular surgical scenario, the surgical rod “R” is placed through the notched opening 24 and positioned across the opening 29 of the operable head 22, see FIG. 4. Alternatively, and in one particular surgical scenario, the opening 29 of the operable head 22 may be mounted over an end of the surgical rod. Knob 14 is rotated, e.g., in a clockwise direction, which, in turn, translates the reciprocating member 8 including the cutting wheels 10 a-10 c distally to an extended position. Knob 14 is rotated until the edges of the cutting wheels 10 a-10 c contact the surgical rod “R” and force the surgical rod “R” into the edges of the cutting wheels 10 d-10 f.

The surgical rod scorer 2 is then rotated (or oscillated) about the surgical rod “R”. The amount or degree of rotation that the surgical rod scorer 2 is rotated (or oscillated) about the surgical rod “R” may depend on the type of surgical rod utilized, the type of spinal fixation device that the surgical rod “R” is attached to, the position of the spinal fixation device on a spine of the patient, etc. For illustrative purposes, it is assumed that the surgical rod scorer 2 is partially rotated 60° about the surgical rod “R”. After each partial rotation of the surgical rod scorer 2 about the surgical rod “R”, the knob 14 is further rotated, which, in turn, translates the reciprocating member 8 including the cutting elements 10 a-10 c distally to maintain contact between the plurality of cutting elements 10 a-10 f and the surgical rod “R” as scoring continues. This sequence of steps continues until the surgical rod “R” is scored to a desired depth. By way of example, when scoring a 5 or 6 millimeter solid titanium rod, one oscillation back and forth through approximately 60 degrees of arc, followed by further compression of the plurality of cutting elements 10 a-10 f against the surgical rod “R” and another oscillation back and forth through an approximate 60 degree arc should score the surgical rod “R” sufficiently to facilitate breaking of the surgical rod “R.”

When the desired depth of the score of the surgical rod “R” is achieved, the knob 14 is rotated, e.g., in a counter-clockwise direction, which, in turn, translates the reciprocating member 8 including the cutting wheels 10 a-10 c proximally and back to the retracted position.

A surgical rod bender (or flexor) 100 (FIG. 9) is utilized to grasp the scored surgical rod “R” on each side of the scored portion “SC” (see FIG. 14) of the surgical rod “R” (FIGS. 10 and 14). Surgical rod benders are common in the art. The surgical rod bender 100 illustrated in FIG. 9 includes a handle 102 that operably couples to two finger portions 104 a and 104 b having respective notched distal ends 106 a and 106 b that are configured to grasp surgical rod “R”.

To cut or separate the scored surgical rod “R”, the handle 102 of the surgical rod bender 100 is squeezed, which, in turn, moves the finger portions 104 a and 104 b away from one another. The scored surgical rod “R” separates along the scored portion of the surgical rod “R” when the fingers 104 a and 104 b have moved a predetermined distance away from one another.

As can be appreciated, the surgical rod scorer 2 according to the present disclosure overcomes some of the previously described shortcomings associated with the aforementioned devices utilized to cut or separate surgical rod “R”. More particularly, scoring the surgical rod “R” initially and, subsequently, flexing the scored surgical rod “R” across the scored portion reduces the shear forces needed to cut or separate the scored surgical rod “R” and, as a result thereof, provides a clean cut or separation of the surgical rod “R”. Moreover, scoring the surgical rod “R” initially and, subsequently, flexing the scored surgical rod “R” across the scored portion reduces and/or eliminates the likelihood of the cut or separated portion of the surgical rod “R” becoming a projectile that has to be recovered or retrieved.

From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, in one particular embodiment, a surgical rod scorer 200 includes a modular type design (see FIGS. 7 and 8). Surgical rod scorer 200 is substantially identical to surgical rod scorer 2. In view thereof, only those features unique to surgical rod scorer 200 are described in detail.

For illustrative purposes, the surgical rod scorer 200 is described in terms of two main components, a handle 204 and an operable head 222. Handle 204 and operable head 222 are configured to releasably couple to one another. Each of the handle 204 and operable head 222 includes a respective handle half portion 204 a and 204 b and a reciprocating half portion 208 a and 208 b (FIG. 8).

By way of example, a tongue and groove configuration is utilized to operably couple the handle 204 to the operable head 222. More specifically, a groove 201 extends through a reciprocating member 208 and a shaft 220 of the handle 204 in a direction that is perpendicular to a longitudinal axis “B-B” that extends through the surgical rod scorer 200 (FIGS. 7 and 8). The groove 201 is collectively defined by handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b. The groove 201 is configured to releasably couple to a corresponding tongue 203 that extends along a reciprocating member 208 and a shaft 220 of the operable head 222 in a direction that is perpendicular to a longitudinal axis “B-B.” Tongue 203 is collectively defined by handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the operable head 222.

To attach the operable head 222 to the handle 204, a user slides the tongue 203 through the groove 201 to a position that corresponds to the individual handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the handle 204 aligning with the individual handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the operable head 222. To facilitate coupling the tongue 203 and groove 201 to each other, the tongue 203 and groove 201 are tapered. This taper prevents the individual handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the handle 204 from uncoupling from the individual handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the operable head 222 when a knob 214 is rotated to return the individual handle half portions 204 a and 204 b and reciprocating half portions 208 a and 208 b on the handle 204 back to a retracted position.

To lock the handle 204 and operable head 222 to one another, a user rotates knob 214 until the reciprocating half portions 208 a and 208 b on the handle 204 push the reciprocating half portions 208 a and 208 b on the operable head 222 a predetermined distance distally at which time the operable head 222 is locked into place.

Once the operable head 222 is locked into place on the handle 204, the surgical rod scorer 200 may be operated in a manner as described above with respect to the surgical rod scorer 2. It is also contemplated that the handle and the operable head could be coupled together using a bayonet style mount assembly.

With reference to FIGS. 15-19E a surgical rod scorer 302 according to an alternate embodiment of the present disclosure is illustrated. Unlike surgical rod scorers 2 and 200, surgical rod scorer 302 includes a scissors-grip configuration. As can be appreciated, this type of surgical rod scorer may prove useful in surgical environments where a user has limited hand use, i.e., a user does not have two free hands to operate a surgical rod scorer.

Continuing with reference to FIG. 15, surgical rod scorer 302 is shown including two shaft members 304 a, 304 b having a generally elongated configuration. Shaft members 304 a, 304 b include respective handle members 306 a, 308 a and jaw members 306 b, 308 b. Handle members 306 a, 308 a are operable to move the jaw members 306 b, 308 b from a spaced-apart configuration (FIGS. 15 and 17) to an approximated configuration (see FIGS. 19A-19E, for example). Jaw members 306 b, 308 b collectively function as working or operable ends of the shaft members 304 a, 304 b to score surgical rod “R.” With this purpose in mind, jaw members 306 b, 308 b include a generally arcuate configuration that facilitates positioning surgical rod “R” therebetween and rotating the surgical rod scorer 302 about the surgical rod “R.” Jaw members 306 b, 308 b are configured to support respective first and second cutting assemblies 310, 312 thereon, see FIGS. 15 and 17.

Referring now to FIGS. 18A and 18B, first and second cutting assemblies 310, 312 (and components associated therewith) are configured to score surgical rod “R” when the jaw members 306 b, 308 b are in the approximated configuration and rotated (or oscillated) about the surgical rod “R.” To this end, first and second cutting assemblies 310, 312 each includes a bifurcated carriage 314, 316 (see FIGS. 18A-18B) each including respective pairs of sidewalls 318 a, 318 b and 320 a, 320 b of suitable configuration (see FIGS. 18A-18B).

Sidewalls 318 a, 318 b and 320 a, 320 b are joined via one or more bushings 322 that are seated within corresponding apertures 324 (see FIGS. 18A-18B). In the illustrated embodiment, sidewalls 318 a, 318 b are joined via two (2) bushings 322 (FIG. 18A) and sidewalls 320 a, 320 b are joined by three (3) bushings 322 (FIG. 18B). As can be appreciated, greater or fewer bushings 322 may be utilized to join the sidewalls 318 a, 318 b and 320 a, 320 b. Bushings 322 include textured (e.g., knurled) side portions 326 a that are configured to facilitate coupling bushings 322 to corresponding apertures 324, see FIG. 18A for example. In addition, bushings 322 include a smooth medial portion 326 b that provides a bearings surface configured to facilitate rotation of cutting elements 328 with respect to the bushing 322 when the surgical rod scorer 302 is rotated (or oscillated), see FIG. 18B for example.

A pair of notches 330 is defined through the sidewalls 318 a, 318 b and 320 a, 320 b (FIGS. 18A-18B) and is configured to removably receive therein corresponding supporting rods 332 that are operably disposed at the jaw members 306 b, 308 b (FIG. 16). As can be appreciated, the notches 330 include a configuration that complements the configuration of the supporting rods 332 to facilitate coupling the supporting rods 332 to the corresponding notches 330. In the illustrated embodiment, the supporting rods 332 are coupled the supporting rods 332 via a press-fit or friction-fit connection. As can be appreciated, this type of connection facilitates removing the supporting rods 332 from the notches 330, such as, for example, when a user wants to “change-out” one or both of the cutting assemblies 310, 312 for a cutting assembly 310, 312 with a different cutting wheel 336 configuration, described in greater detail below.

Supporting rods 332 are supported at the jaw members 306 b, 308 b via corresponding apertures 334 that extend through the jaw members 306 b, 308 b (FIG. 16). In accordance with the present disclosure, the supporting rods 332 are configured to maintain the bifurcated carriages 314, 316 in substantially fixed orientation when the shafts 304 a and 304 b are moved to the approximated configuration and surgical rod “R” is positioned between the jaw members 306 b, 308 b; this facilitates keeping the cutting wheels 336 in contact with the surgical rod “R” when the surgical rod scorer 302 is rotated (or oscillated).

Continuing with reference to FIG. 16, shaft members 304 a, 304 b are operably coupled to one another via a pivot pin 338 that resides in apertures 340 a, 340 b that extend through each of the shaft members 304 a, 304 b. A washer 342 of suitable configuration is positioned between the shaft members 304 a, 304 b and utilized to maintain a predetermined distance between the shaft members 304 a, 304 b when the shafts members 304 a, 304 b are in an assembled configuration. Moreover, a pair of lock washers 344 is disposed within apertures 340 a, 340 b and are configured to receive a portion of the pivot pin 338 therethrough to maintain the pivot pin 338 within the apertures 340 a, 340 b.

Unlike the aforementioned surgical rod scorers, e.g., surgical rod scorer 2, surgical rod scorer 302 is configured to utilize selectively removable cutting assemblies 310, 312 of various configurations, e.g., diameters. For example, and as illustrated in FIGS. 19A-19E, surgical rod scorer 302 may be configured to utilize cutting assemblies 310, 312 including cutting wheels 336 having diameters equal to about 3.5 mm (FIG. 19E), 4.5 mm (FIG. 19D), 5.5 mm (FIG. 19C), 6.0 mm (FIG. 19B), ¼ inches (FIG. 19A), or other suitable diameters not disclosed herein. Cutting wheels 336 are configured to function as described above with respect to surgical rod scorer 2. Accordingly, the cutting wheels 336 are not described in any further detail.

One or more access apertures 346 (FIGS. 15-17) are defined through the jaw members 306 b, 308 b and are configured to facilitate uncoupling the cutting assemblies 310, 312 from respective jaw members 306 b, 308 b. In particular, the aperture(s) 346 is configured to receive one or more suitable devices therein to “push” the cutting assemblies 310, 312 out from the jaw members 306 b, 306 b so that a user may replace or change the cutting assemblies 310, 312 with a new (e.g., same size cutting wheels 336) or different (e.g., different size cutting wheels 336) cutting assembly 310, 312. In the illustrated embodiment, each of the jaw members 306 b, 308 b includes an aperture 346, however, the aperture 346 defined through jaw member 306 b is not explicitly shown.

Use of the surgical rod scorer 302 is similar to that of surgical rod scorers 2 and 200. Unlike surgical rod scorers 2 and 200, however, surgical rod scorer 302 may be utilized with one hand to score surgical rod “R” (FIG. 14). In particular, a user may position the jaw members 306 b, 308 b of the surgical rod scorer 302 around surgical rod “R.” Thereafter, a user may squeeze the handle members 306 a, 308 a toward one another to approximate the jaw members 306 b, 308 b including the cutting wheels 336 thereon toward one another to press the cutting wheels against the surgical rod “R.” When the cutting wheels 336 contact the surgical rod “R,” under pressure, a user rotates (or oscillates) the surgical rod scorer 302 as described above. With each oscillation, the user may squeeze the handle members 306 a, 308 a toward one another, which, in turn, causes the cutting elements to extend toward the surgical rod “R” and increase the depth of the score of the surgical rod “R.” thereby maintaining pressure between the cutting wheels 336 and the surgical rod “R” during the rotating or oscillating action.

Once the surgical rod “R” is scored to a suitable depth, the surgical rod bender 1000 may be utilized as described above to cut or break the surgical rod “R.”

As noted above, if needed, a user may uncouple the cutting assemblies 310, 312 from the jaw members 306 b, 308 b to replace them with cutting assemblies 310, 312 having smaller or larger diameter cutting wheels, see FIGS. 19A-19E for example.

As can be appreciated, the surgical rod scorer 302 overcomes the aforementioned shortcomings associated with convention surgical rod cutters. In addition, the surgical rod scorer 302 also provides a user with the ability to simply and easily score surgical rod “R” with one hand.

With reference to FIGS. 20A-20B a surgical rod scorer 402 according to an alternate embodiment of the present disclosure is illustrated. Surgical rod scorer 402 is similar to surgical rod scorer 302. In view thereof, only those features unique to surgical rod scorer 402 are described in detail.

Handle members 406 a and 408 a include a generally straight configuration when compared to the handle members 306 a and 308 a; this straight configuration facilitates scoring surgical rod “R” that is not easily accessible to a user, e.g., surgical rod “R” that is “hard to reach.”

Unlike surgical rod scorer 302, surgical rod scorer 402 includes handle members 406 a and 408 a that have respective ring portions 401 and 403 disposed at a proximal end thereof. Ring portions 401 and 403 are configured and dimensioned to receive a finger of a user therein to facilitate grasping the surgical rod scorer 402.

One or more engagement members 405 and 407 are provided adjacent respective ring portions 401 and 403. Engagement members 405 and 407 include at least one interlocking tooth 405 a and 407 a thereon. In the illustrated embodiment, engagement members 405 and 407 include a respective plurality of interlocking teeth 405 a and 407 a that are configured to matingly engage one another when the handle members 406 a and 408 a are moved a predetermined distance toward one another. Interlocking teeth 405 a and 407 a are configured to maintain jaw members 406 b and 408 b in one or more predetermined approximated configurations when the interlocking teeth 405 a and 407 a are moved to one or more corresponding engaged configurations. The one or more corresponding engaged configurations correspond to a specific pair of interlocking teeth 405 a and 407 a that are engaged with one another. For example, when one of each of the interlocking teeth 405 a and 407 a are engaged with one another, the jaw members 406 b and 408 b are maintained in a first predetermined approximated configuration. Likewise, when two of each of the interlocking teeth 405 a and 407 a are engaged with one another, the jaw members 406 b and 408 b are maintained in a second predetermined approximated configuration. In the second predetermined approximated configuration jaw members 406 b and 408 b are closer to one another than when in the first approximated configuration. The number of approximated configurations that the jaw members 406 b and 408 b may be maintained in is proportional to the amount of teeth that define the plurality of interlocking teeth 405 a and 407 a. As can be appreciated, movement of the jaw members 406 b and 408 b through the approximated configurations moves the cutting wheels 446 closer to one another, which, in turn, provides an increased a score depth of the surgical rod “R” when the surgical rod scorer 402 is rotated (or oscillated).

It is within the purview of the present disclosure to utilize engagement members 405 and 407 that include other mating (or locking) devices and/or methods to maintain the jaw members 406 b and 408 b in one or more of the approximated configurations. For example, clasps, pins, buttons, ratchets, pawls, and the like may be utilized with the surgical rod scorer 402 to maintain the jaw members 406 b and 408 b in one or more of the approximated configurations. As can be appreciated, certain modifications may need to be made to the surgical rod scorer 402 to accommodate these engagement devices and/or methods.

A user may utilize finger pressure (or other suitable methods) to disengage the interlocking teeth 405 a and 407 a from one another.

Operation of the surgical rod scorer 402 is similar to that of surgical rod scorer 302. Unlike surgical rod scorer 302, however, jaw members 406 b and 408 b may be maintained in one or more of the approximated configurations via the interlocking teeth 405 a and 407 a as the surgical rod scorer 402 is rotated (or oscillated).

While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

For example, in the embodiment of FIGS. 1-6 the entire device could be entirely reusable or entirely disposable. Moreover, the plurality of cutting elements 10 can be entirely reusable or entirely disposable. In the embodiment of FIGS. 7 and 8, the entire device could be entirely reusable or entirely disposable, or, could be partially reusable or disposable.

It is contemplated that different operable heads 222 may be provided that are configured to couple to the handle 204 for cutting different surgical rods, rods of different material, or for different diameter rods.

It is contemplated, that the knobs 14/214 can be replaced with different types of motion. For example, instead of a rotatable knob 14/214, the knobs 14/214 may be configured for translation along the longitudinal axis “A-A.” As a further alternative, a pistol type grip that imparts longitudinal motion could be substituted for advancing the reciprocating member to assure contact between the cutting elements and the rod as scoring takes place. The handle could also include a ratchet mechanism to assure the continued application of force between the cutting elements and the rod as the cutting elements are advanced between oscillations of the device about the rod. 

The invention claimed is:
 1. A surgical rod scorer, comprising: a handle having a shaft extending therefrom and defining a longitudinal axis; a knob supported on a proximal end of the handle and rotatable about the longitudinal axis; an operable head removably coupled to a distal end of the shaft configured to support a first cutting assembly thereon, the operable head having an opening configured for receiving a surgical rod therethrough; a reciprocating member operably disposed and axially translatable within the handle, the reciprocating member including a proximal end operably coupled with the knob and a distal end supporting a second cutting assembly thereon; and a drive member operably coupling the proximal end of the reciprocating member to the knob, wherein rotation of the knob about the longitudinal axis translates the reciprocating member between a retracted position and an extended position, the second cutting assembly configured for scoring a surgical rod positioned in the opening with the reciprocating member in the extended position.
 2. The surgical rod scorer of claim 1, wherein the first and second cutting assemblies are oriented in a common plane along a centerline of the surgical rod scorer.
 3. The surgical rod scorer of claim 1, wherein a guide member is disposed on an interior surface of the handle and is configured to couple to a slot disposed on the reciprocating member, the guide member movable within the slot to align the reciprocating member with respect to the handle.
 4. The surgical rod scorer according to claim 1 wherein a rod extends from the knob and is operably coupled to the drive member such that the knob is axially stationary with respect to the longitudinal axis.
 5. The surgical rod scorer according to claim 4, wherein a portion of the rod is threaded.
 6. The surgical rod scorer of claim 5, wherein the proximal ends of the reciprocating member and the handle include openings for receiving the rod therethrough.
 7. The surgical rod scorer of claim 6, wherein the rod includes an annular flange disposed thereon, the annular flange positioned in a cavity between the opening and the proximal end of the reciprocating member and the opening at the proximal end of the handle, the annular flange maintaining the knob in a fixed position along the longitudinal axis.
 8. The surgical rod scorer of claim 1, wherein each of the first and second cutting assemblies includes a plurality of cutting wheels rotatably seated within a corresponding plurality of bushings, the plurality of bushings facilitating rotation of the plurality of cutting wheels during rotation of the surgical rod scorer about a surgical rod.
 9. The surgical rod scorer according to claim 1, wherein the first cutting assembly includes a first cutting wheel, and the second cutting assembly includes a second cutting wheel.
 10. The surgical rod scorer according to claim 1, wherein the operable head is locked to the handle when the reciprocating member is translated from the retracted position towards the extended position. 